Glass tank wall and method of constructing it



Jan. 13, 1942. G. J. EASTER GLASS TANK WALL AND METHD OF CONSTRUCTING IT 'Filed May 14, 1938 HnN/// INVENTOR. GEORGE J. EASTER ATTORNEY.

I. Patented Jan. 13, 1942 azaus GLASS TANK WALL METHOD CONSTRUCTING IT George J. Easter, Niagara Falls, N. Y., assigner to- The Carborundum Company, Niagara Falls, N. Y., a corporation of Delaware f Application May 14, 193s, serial No. 207,915

7 claims. (c1. 1o-54) This invention relates to the construction of glass tank furnaces and particularly to glass tanks in which refractory blocks of high thermalv conductivity are used to line the melting'and rening chambers. When blocks of high thermal 'Y conductivity, such asthose cast from fused alumina, are used in lining glass tanks, the heat from the molten glass permeates the blocks with the result that the temperature of the louter portions of the blocks is very close to that Aof the molten bath. j i In the use of bonded refractory blocks for lining glass tanks, it has been found inadvis'abl'e tov insulate the inner lining due to the subsequent marked increase in the rate of corrosion as' the temperature of the lining is increased. For this reason most glass tanks have been operated at an extremely low. thermal efficiency due to the heat loss through the walls. y

The 'search for a material which would Withf stand higher temperatures( has resulted in the lperature.

The composition of the packing or joint mate-"-`A material so used shouldfbe vone especially adzapted for the purpose and isv of such composition that it will react with the glass being melted so as to render it more viscous 'by the formation of a reaction product that lcorlgeals at a higher ,tem-

rial may be varieddependent upon the composition of the glass being melted in the tank,` but is recent development of refractory blocks made by casting' molten` refractory oxides such as y A moved from the hot face of the tank lining,k and I prefer to restrict its application to parts of the alumina into the required forms. This ty'pe of material has met with some success because of its increased resistance to molten glass and s'lags at high temperatures, but its high thermal con! ductivity has presented4 a serious problem` in keeping the molten glass from seeping through the joints between blocks, particularly vwhen the always such that when it comes in contact with `the molten glass .it will react or fuse with the glass to form a new material having a higher l' melting point or a higher viscosity at a given I have found that'for most glasses a highly vsiliceous materialcan be used vvery effectively for thisl temperature'than the original glass.

purpose. However, where a tank is used consistently in melting one kind of glass the packing material may be chosen so as to be one which works particularly well withthat onevglaSS..

While this packing material maybe placed .along the entire block joint it usually becomes effective at a point in the'joint somewhat rejoint'away from the hot face. I This material may-be used dry, orfmay, in certain cases, be moistened enough to cause it to form a stiff paste Y ,which is then smeared on the desired portions outer faces of the refractories-have-been -in^ sulated. It has been common practice therefore to forego insulation of the back of the blocks in order to keep thei joints between Vthem cool enough to congeal the glass before it reached the outer faces. This has resulted in operation under high heat losses and even lower thermal eiliciency than with the old type blocks and so to a large part the advantage of increased corro# sion resistance has been counteracted.

vI have overcome the diculties and disadvantages described above by the insertion of 'means between the glass tank blocks to congealv or increase in viscosity any glass that starts to seep through the joints. This higher viscosity retards or prevents its further travel through the joint. This I do chemically -by the use of a packing material which will react with the glass to render it more viscous, or mechanically by in- ;ertion in the joint of cooling members to render alle glass congealed.

One method by which I carry out my invention ,s as follows: In setting up the blocks, I put the ipecial packing material in the outer portion of :ach joint between the blocks. 'I'he packing of the block faces which adjoin to form the joint.

thus filling in any irregularities inthe face with` this*y packing materialV to form a smooth surface causing a close fit between thel blocks for the entire length of each joint.l

The reaction of thismaterial with the glass which penetrates the jointraises the congealing temperature and viscosity of the original glass,

ycausing it to become solidified or so viscous that y thejoint is'substantially sealed and any further penetration ofthe joint by the glass is prevented. The viscosity is, moreover, so high that there is little tendency of the joint filling compound` to l work back out into the glass tank.

' The reaction product formed by union of the n packing material with vseepage glass often has a much higher surface tension withl respect to the face of the refractories used and does notwet the refractory so readily as the glass being melted. This effect lowers the rate of .erosion within the joint of the cast blocks which make up the lining and so constitutes another beneficial result of 'the use of my lspecial packing material.

`In accordance with another vmodification of my invention, I provide the block faces which form the joints with recesses or indentations which match in adjoining block faces to form enclosures in the outer portions of the joints. |Ihese enclosed spaces are then filled with the reactive material referred to above. Thus, an adequate supply of the reactive packing material is provided to unite and form the more viscous glass with any molten glass that penetrates the joint as far as the recesses.

' Where the joints are vertical, additional reactive material, to replace that taken up by the glass, can be fed into the joints by means of a funnel and permitted to flow down into the joint. Granular orl powdered zirconium silicate is an example of a material which is adapted for use in this manner since it is heavier than the glass and tends to sink down the vertical recesses whenever the glass in them is suiciently fluid to be dangerous and at the same time is soluble in most glasses to a degree which Vraises the viscosity.

As stated above, the reactive material provided in joints must be adapted to-at least inlcrease the viscosity, if not to cause the glass to congeal.

of glasses may be made more viscous by contact with powdered lime. v

Other means by which the seepage of glass through the wall joints may be reduced or eliminated are metallic or other cooling members po sitioned in the joints between the blocks so as to conduct the heat away from the molten glass with sufficient rapidity to cool the glass to the point where it becomes extremely thick and viscous, if not solidified. One way of doing this is to have the outer portion of adjoining block faces cut back so as to form a slot in the rear portion of the joint. A thin bar of highly heat-conductive metal and which is broad enough to protrude sev-- eral inches outwardly from the joint is then inserted in this slot. In this way, the glass as it progresses through the joint comes in contact with this bar of metal and is chilled and solidifies.

It then seals the joint and prevents further pasl sage of glass.

Another modification of my invention which is very effective, although costly to install, comprises the use of metal pipes embedded in the outer portion of the joint and fitting closely between the blocks. Blocks having recessed portions that match to form an enclosure in the joint for holding the pipe are useful in this modi'- fication. The pipe may have a flange that projects inwardly along the joint in order to cause the glass to congeal before it reaches the outside of the joint. In operation, water is circulated through the pipe and heat is thereby conducted away from the joint. Any glass entering the joint freezes and effects a sealing of the joint AThe rate of circulation of the water may be controllgd :so as to-remove no more heat than is essentiallo keep the joint sealed.

If desired,vboth the reactive means and the cooling means can be used in setting up the lining ofaglasstank. '.f

In the accompanyingvdrawing:

Figure 1 is a fragmentary horizontal sectional view of a glass tank wall using recessed blocks having joints filled with potentially reactive material.

Figure 2 is a fragmentary horizontal sectional View of'a glass tank wall using recessed blocks and having a heat conductive metal bar inserted in and protruding outwardly from the joint to conduct heat away from thejoint.` I

Figure 3 is a fragmentary horizontal sectional view of a glass tank wall using packing material in the joints and shows a further modified form of undercut joint.

Figure 4 is a fragmentary horizontal sectional view of a glass tank wall having joints recessed to hold a hollow flanged pipe for circulating water to seal the joints.

Figure 5 is a fragmentary horizontal sectional view of a glass tank wall similar to Figure 4 but having the pipe with the exception of the flange positioned outside of the joint between the wall blocks.

Figure 6 is a vertical cross-sectional view across the line VI-VI of Figure 1 and showing provision for the addition of material by means of gravity feed from a funnel (funnel not shown in Figure 1). v -Y In the various figures, the joints 2 between blocks I are recessed near the outer portions as shown by numerals 3. These recesses 3 may be of any desired shape and may be lled with reactive packing material 6 as shown in Figures 1 and 3 where the recess acts as a reservoir for this joint material; or as shown in Figures 2, 4

and 5 the recess 3 may be shaped to receive heat conductive cooling members. In Figure 2 the cooling strip l is in the form of a metal bar which fits in the recessed portion 3 and extends out through the insulation 4 to a metal shell 5. Under certain conditions this heat conducting member may well be of a refractory such as silicon carbide rather than of metal l AIt is also within the scope of my invention to have such bars extend out into the open air beyond the insulation in order to be more effectively cooled by convection.

In Figures 4 and 5 the cooling member is a pipe 8 equipped with a flange 9 extending inwardly Kalong the joint 2 and filled with circulating water. In Figure 5 the pipe 8 is not positioned inthe joint but is located vin the layer of insulation 4 just at the back of the joint 2.

In Figure 6, numeral Il) represents a funnel or other feed hopper from which additional material is allowed to sift down into the joint space. l as needed. Other numerals have the same signicance as in Figure l.

While the drawings have depicted various modilications, my invention is not limited to the few detailed types given therein. The drawings show horizontal cross sections 0f walls having vertical joints, but it is within the scope of the present invention to employ packing material and/or meprimarily for use with fgcast :refractory blocks vbecause of their high thermal conductively, .-it

mayalso be used to advantage.inizconncction with bonded refractories.

Having clearly described and explained the .present invention by means of .thea abov detailed examples,V what I claim is:

1. ,A glass tank wall comprising refractory blocks having a jointbetween adjoining blocks, anindentation in the face of one of said blocks adjoining `lsaid joint, said indentation forming a substantially'enclosed space witliin'the outer portion of said joint, and reactive `paekingmaterial l in said enclosed :space for reacting with and rendering glass Whichlhas penetrated said v'joint so 'viscous .as tosubstantially prevent .its further movement through saidjoint.

2. A glass tank `wall comprising heat .conductive cast lrefractory :blocks having va 'joint between` adjoining blocks, isaid joint 'having 'itslouter portionllediwitha material potentially-reactive with glass so `as :to render glass whichlpenetrates .said joint .so viscous as to .substantially prevent its ,further movement through :said joint.

3. The :method Vof preventing seepage .of ,molten glass through the 'joints between adjoining blocks of a glass tank lining which comprises .fillinguthe outer portion of said ,joints with a material .poftentially reactive with 'the glass so as to raise the viscosity of the glass and substantially prevent.;

its further movement :through said joints..

4. A glass tank wall comprising refractory blocks backed by a .layer of insulation v'ancllhaving joints between adjoining blocks, said joints having their outerv portions filled Withamaterial potentially more reactive with Vglass thanisthe material of the block and of such nature vas `to ,render glass which penetrates `said joints into contact with said materialvsozviscousms substantially to prevent its iiuitther `movement through said joints.

5. A glass tank wall comprisingheatrconductive cast-refractory blocks backedbyea'layer of insulachannel of increased sectional :area `IWithin the outer portion of said joint, substantially filled with comminuted acidic refractory material.

GEORGE LEASTER. 

